“If he wants to engage in personal attacks from the past, that’s his prerogative. So be it,” Clinton said, vowing that she’d continue to run as a women’s rights candidate on issues such as equal pay and abortion rights.

Trump has argued that Clinton doesn’t have moral standing to run as a women’s rights candidate, alleging that she sought to bully into silence Bill Clinton’s accusers of sexual impropriety.

It comes as Bill Clinton has played a more visible role in his wife's presidential campaign. On the campaign trail, both have sought to deflect questions over his past by refusing to engage with Trump.

Clinton on Sunday called that avenue of attack a “dead end.”

“It’s been fair game going back to the Republicans for some years,” Clinton said. “They can do it again if they want to, that will be their choice as to how to run in this campaign. It didn’t work before, it won’t work again because people are focused on not the past, but the future.”

“They can do whatever they want, more power to them,” she added. “I think it’s a dead-end, a blind alley for them, but let them go. I’m going to talk about the differences between us because I think that’s what Americans care about.”